BQ25895: bq25895 VSYS drop to 0

Sammi Shang

Part Number: BQ25895

Dear team,

During customer's test, there was one board that VSYS will drop to 0 @55 degree C. Others are normal. VBUS is not on when fault happens. If add VBUS, the VSYS will become normal. It seems BATFET is off, I could make sure that battery voltage is about 4.0V and no over-current happen. 25 degree C has not seen same issue.

Thanks.

Best regards,

Sammi

over 5 years ago

0 Ning T over 5 years ago

TI__Guru 57341 points

Sammi,

Could you please provide the followings?

What are the test conditions such as VBUS, VBAT, IBAT, VSYS, ISYS when the behavior happens?
What are all the register values when VSYS drops?

Thanks,

Ning.

0 Sammi Shang over 5 years ago in reply to Ning T

TI__Expert 4450 points

Hi Ning,

Thanks for your reply.

1, No vbus, vbat 4.1V. Isys no over load happen, common load.

2. Vsys drop to 0, all system power down and could not save configuration.

Currently there was one board with this phenomenon, and only happen when temperature rise to 55.

Thanks.

Best regards,

Sammi

0 Ning T over 5 years ago in reply to Sammi Shang

TI__Guru 57341 points

Sammi,

What are all the register values when VSYS drops? You may use external power supply for I2C communication. The charger can support I2C at VBAT=4.1V.

Thanks,

Ning.

Power management

Power management forum

BQ25895: bq25895 VSYS drop to 0